Radio frequency transmissions can be used to form a communication network in which messages are exchanged between network devices. However, RF signals can be susceptible to spoofing in which an intruder attempts to use the network to send unauthorized messages. To the extent that the intruder is able to mimic RF characteristics of the communication signal, other network devices may be unable to distinguish the spoofed messages from authentic communications.
Other types of communication systems rely on reflected signals to pass messages between devices. Such reflected communications can have a limited operating range as signal power falls off rapidly with distance. Moreover, reflected communication systems often depend upon a precise alignment between the transmitting element and the reflecting element. If this alignment is disturbed or cannot be established, communications may fail. These shortcomings can lead to unreliable communications, particularly under difficult conditions such may be experienced in a battlefield environment.